Myocardial infarction is one of the most common diagnosis occurring in hospitalized patients in Western countries. In the United States, approximately 1.5 million myocardial infarctions occur each year. Myocardial infarction generally occurs with abrupt decrease in coronary blood flow that follows a thrombotic occlusion of a coronary artery previously narrowed by atherosclerosis. Once severe stenosis of a coronary artery has reduced the cross-sectional area by more than approximately seventy percent, a patient is likely to develop clinical manifestation of coronary artery disease, which includes angina pectoris, myocardial infarction, ventricular arrhythmia, and sudden death. Therefore, in patients with severe coronary artery disease, aggressive medical therapy and mechanical revascularization, including percutaneous transluminal coronary angioplasty, coronary atherectomy, coronary stent placement, and coronary artery bypass grafting surgery, are often indicated to improve a patient's quality of life and survival.
Excellent long-term results have been obtained with conventional coronary artery bypass grafting surgery. However, significant mortality and morbidity still exist due to the use of cardiopulmonary bypass for circulatory support and the traditional method of access by median stemotomy. To alleviate these problems, an endovascular or port-access technique for cardiopulmonary bypass and cardioplegic arrest has been developed for use in cardiac surgery. This peripherally based system achieves aortic occlusion, cardioplegia delivery, and left ventricular decompression. Thus, coronary revascularization and various cardiac procedures, which include valvular repair, septal defect repair, atherectomy, aneurysm repair, and correction of congenital defects, can be effectively performed in a less invasive fashion.
Traditionally, multiple cannulation sites are required for placement of arterial and venous return cannulas for cardiopulmonary bypass. Moreover, an additional access mechanism is generally required for insertion of these cannulas. Problems associated with these techniques are that they may increase a patient's surgical morbidity. A need therefore exists for minimally invasive devices and methods which facilitate delivery of medical therapy and provide an access mechanism for cannulation of body tissues.